Improved method for the detection of creatinine

摘要

Disclosed is an improvement to the assay for creatinine in fluid test samples by contacting the test sample with a reagent formulation containing cupric ions, a hydroperoxide and an oxidizable dye. The improvement involves the inclusion of one or more selected quinolines in the reagent formulation. When the quinoline is substituted with methyl in the 2-5 position and/or a methoxy in the 2-6 position auto-oxidation of the oxidizable dye is reduced. When the quinoline is further substituted in an otherwise unsubstituted carbon atom in the 2-8 position, the assay's resistance to interference from hemoglobin and ascorbate is increased.